8 PROCEEDINGS OF THE NATIONAL MUSEUM vol.76 



Thorax black, with a round polished area on each side between the 

 dorsocentral bristle and the notopleura surrounded by one or two 

 rows of white flattened hairs; another polished area on each side, 

 behind the first mentioned, separated by the suture and a few of the 

 same white hairs; the anterior middle part of the thorax is slightlj" 

 pollinose and has two rows of acrostichal hairs which are white and 

 slightly flattened; behind the suture this middle region is a little 

 more pollinose and has more of the hairs. There is one very distinct 

 dorsocentral bristle well before the suture and another slightly behind 

 it; one farther back is regarded by Hendel as being acrostichal (pre- 

 sutural) , although in this species it seems to be almost exactly in line 

 with the dorsocentrals; the scutellum is globose, polished, and has 

 two pairs of black bristles; postscutellum as in gihba. Halteres dark 

 yellow with brownish knob. 



Abdomen black; anterior portion of segments two, three, and four 

 a little pollinose and bearing white hairs, the posterior portion more 

 shining and bearing black hairs which form a rather distinct band on 

 the second and third segments; the fourth segment is almost as 

 long as the preceding two. On the ventral side the abdomen 

 shows a wide space of membrane and very narrow sternites; the 

 membrane, however, is not swollen and not visible from above. 



Wings rather milky with four brown bands, the two middle ones 

 connect anteriorly and the space between them widens rapidly to the 

 hind border, the fourth band is entirely separated from the third and 

 does not quite touch the costa except behind the fourth vein. 



Female. — Ovipositor shining black with rather numerous black 

 hairs, as long as the three preceding segments, tapering rather 

 rapidly. 



Length, male 3-3.4 mm., female 4.4-6 mm. 



Redescribed from numerous specimens. Twenty-nine specimens 

 were reared from galls on Solidago at Great Falls, Va., by C. T. 

 Greene (Hopkins No. 14819a); the types of setigera include the fol- 

 lowing lots: Four specimens from Kirkwood, Mo., reared in 1884 by 

 Miss Mary E. Murtfeldt "from leafy rosulate galls on Solidago nemo- 

 ralis"; three specimens reared in Virginia, near Washington by Theo. 

 Pergande from galls on Aster which deform the stem and dwarf the 

 plant; other unreared types oi setigera are from Bristol, R. I. (Burgess), 

 southern Georgia (Morrison), Baldwin, Kans. (Bridwell); additional 

 unreared specimens of atra are from La Fayette, Ind. (Aldrich), French 

 Creek, W. Va. (F. E. Brooks), Cherryfield, Me. (F. H. Lathrop), 

 Smiths Cove, Nova Scotia (C. A. Good), and several specimens col- 

 lected in the neighborhood of Washington, D. C, by Shannon, Walton, 

 Bridwell, and Kraus. 



The type was in the Winthem collection and is now in the Vienna 

 Natural History Museum; Hendel gave some notes on it in 1914. 



